- On The Frontlines Of Freedom
- On the Future of History
- On the Ganges
- On the Genealogy of Mortals
- On the Good Life
- On the Greenbelt
- On the Grid
- On the Hunt in Baghdad
- On the hurricane of August 1772
- On the Importance of Being an Individual in Renaissance Italy
- On the Indian Trail - Stories of Missionary Work among Cree and Salteaux Indians
- On the Indian Trail: Stories of Missionary Work among Cree and Salteaux Indians
- On the Irrawaddy / A Story of the First Burmese War
- On the Judgment of History
- On the Lady Chapel in Chester Cathedral
- On the Laps of Gods
- The Rights of War and Peace
- On The Laws Of Japanese Painting
- On the Line
- On The Makaloa Mat
- On the Margins of a Minority
- On the Margins of Crusading
- On the Medieval Origins of the Modern State
- On The Missionary Trail
- On the Motion of the Heart and Blood in Animals
- On the Mystery of Innovation
- On the Nature of Things
- On the Nature of War
- On the Ocean
- On the Origin of Evolution
- On the Origins of Global History
- On the Origins of Jewish Self-Hatred
- On the Origins of Judaism
- On the Plains with General Custer
- On the Plains, and Among the Peaks: or, How Mrs. Maxwell Made Her Natural History Collection
- On the Potomac River
- On The Psychology Of Military Incompetence
- On the Religious Frontier
- On the right of the British line: World War 1
- On the Right to Rebel against Governors
- On the Road to Hungnam, North Korea
- On The Road To Kut, A Soldier’s Story Of The Mesopotamian Campaign [Illustrated Edition]
- On the Road to West Egg
- On the Run in Nazi Berlin
- On the Run with Bonnie & Clyde
- On the Screen
- On the Seven Seas
- On the Shores of the Great Sea
- On the Shores of the Great Sea (Serapis Classics)
- On the Shortness of Life
- On the Shoulders of Our Ancestors
- On the Spartacus Road
- On the Spirit of Rights
- On the Sublime
- On the Sultan's Service
- On the Threshold of Central Africa (1897)
- On the Threshold of the Holocaust
- On the Town in New York
- On the Track of Ulysses Together with an Excursion in Quest of the So-called Venus of Melos: Two Stu...
- On The Trail of Delusion
- On The Trail Of Deserters
- On the Trail of Deserters. A Phenomenal Capture
- On the Trail of Genghis Khan
- On the Trail of Grant and Lee
- On the Trail of Mary, Queen of Scots
- On the Trail of the Immigrant
- On the Trail of the Indo-Europeans: From Neolithic Steppe Nomads to Early Civilisations
- On the Trail of the Real Robin Hood
- On the Trail of the Women Warriors
- On the Trail of the Yorks
- On the Trails of Tradition
- On the Treadmill to Pearl Harbor
- On the Viking Trail
- On the Warm Shores of Africa - The Ethnic Wars That Left a Legacy of Distrust - The Sequel to A Fami...
- On the Warpath in the Pacific
- On the Wings of Geezers
- On the Wings of Time
- On the Word of a Jew
- On the Writing of History
- On Thermonuclear War
- On these Promising Shores of the Pacific
- On This Day
- On This Day in California History
- On This Day in Connecticut History
- On This Day in Detroit History
- On This Day in Indianapolis History
- On This Day in Kingsport History